Roll stand with axially shiftable working rolls

Abstract

A roll stand comprises a plurality of axially shiftable working rolls, each attached by supporting members axially slidably to a guide member which is movable vertically adjustably against the side of a cylinder block installed in the roll stand housing. Axially shifting hydraulic cylinders are provided to axially shift the working rolls by acting on the guide pieces. In particular a plurality of balancing hydraulic cylinders are installed in laterally projecting shoulders in the cylinder blocks behind each other in the axial shifting direction of the rolls and act on the working rolls to provide balancing and bending forces. In order to install only cylinder blocks of reduced size, the balancing hydraulic cylinders operating downwardly and the balancing hydraulic cylinders taken individually along the axial shifting direction project alternately downward and upward from the shoulder of the cylinder block associated with them and act on the guide pieces on which the working rolls are mounted.

I claim: 
     
       1. In a roll stand comprising a plurality of axially shiftable working rolls, each of said working rolls having at least one structural member attached thereto; a plurality of guide pieces, each of said guide pieces having one of said working rolls connected axially slidably thereto by at least one of said structural members, said guide pieces being slidable substantially vertically along at least one cylinder block by at least one balancing hydraulic cylinder mounted in one of said cylinder blocks for balancing and working roll bending, and at least one of said guide pieces is associated with at least one axially shifting hydraulic cylinder which causes said axial shifting of one of said working rolls, the improvement wherein a plurality of said balancing hydraulic cylinders acting upon said structural members having said working rolls connected thereto with balancing and bending forces are positioned in at least one projecting shoulder of said cylinder blocks, said balancing hydraulic cylinders are displaced from each other in a direction parallel to the axes said working rolls, each of said balancing hydraulic cylinders having a balancing cylinder piston rod, said balancing cylinder piston rods of said balancing cylinders taken individually along said direction parallel to said axis of said working rolls projecting alternately downward and upward from said shoulder to engage and act on said guide pieces of said working rolls, said axially shifting cylinder being located in said one of said guide pieces, a shifting cylinder piston rod of said axially shifting hydraulic cylinder being respectively provided with a coupling body attached to the free end of said shifting cylinder piston rod, said coupling body being connected to and providing a means of attachment to a lug jutting out from one of said structural members. 
     
     
       2. The improvement according to claim wherein said balancing hydraulic cylinders are positioned at the same height in said shoulder of said cylinder blocks and the axes of said balancing hydraulic cylinders associated with one of said cylinder blocks lie in a common substantially vertical plane. 
     
     
       3. The improvement according to claim wherein both the top surface and the bottom surface of the pistons of said balancing hydraulic cylinders are acted upon and said balancing cylinder piston rods are attached to said guide pieces. 
     
     
       4. The improvement according to claim 1 wherein said axially shifting hydraulic cylinders causing said axial shifting of said working rolls are positioned in said guide pieces. 
     
     
       5. The improvement according to claim 4 wherein the shifting cylinder piston rods of said axially shifting hydraulic cylinders are connected to said structural members of said working rolls. 
     
     
       6. The improvement according to claim 1 wherein each of said coupllng bodies is provided with a slider engaging and overlapping said lugs, said slider being retractable along a guide. 
     
     
       7. The improvement according to claim 6 wherein said structural members of said working rolls are provided with a connecting body having said lug jutting out therefrom. 
     
     
       8. The improvement according to claim 7 wherein said slider is held braced in position for operation by a compressible spring. 
     
     
       9. The improvement according to claim 8 wherein said slider is provided with form-fitting structural elements for engagement with and coupling to a sliding carriage, which is operated by an applied force, when said coupling member is in a base post on in which said coupling member is adjacent said guide piece. 
     
     
       10. The improvement according to claim 9 wherein said slider has two locking ridges and two supporting lips, which engage slidably two bracketlike ends of said coupling body to provide a strong, but detachable, coupling between said slider and said coupling body. 
     
     
       11. The improvement according to claim 9 wherein said plurality of balancing hydraulic cylinders is divided into a plurality of groups of two adjacent balancing hydraulic cylinders, wherein the spacings between said two adjacent balancing hydraulic cylinders of each of said groups are smaller than the spacings between each of said balancing hydraulic cylinders next to each other in adjacent ones of said groups. 
     
     
       12. The improvement according to claim 11 wherein said cylinder blocks have a lateral projection positioned between two of said adjacent groups of said balancing hydraulic cylinders, and that in the vicinity of said projection said cylinder blocks have an additional balancing hydraulic cylinder for balancing of at least one intermediate or supporting roll of said roll stand. 
     
     
       13. The improvement according to claim 12 wherein said plurality of balancing hydraulic cylinders comprises four balancing hydraulic cylinders. 
     
     
       14. The improvement according to claim 13 wherein two of said cylinder blocks are provided and said cylinder blocks have different thicknesses. 
     
     
       15. The improvement according to claim 1 wherein said working rolls are arranged displaced slightly in the rolling direction from the vertical plane containing the axes of at least one supporting roll of said roll stand. 
     
     
       16. The improvement according to claim 1 wherein each of said balancing hydraulic cylinders associated with one of said cylinder blocks is positioned displaced from a central vertical plane. 
     
     
       17. In a roll stand of a strip rolling mill of the type in which a pair of working rolls is disposed between a pair of backing rolls, said stand comprising a frame having uprights provided with respective windows, said working rolls each being journaled at each of said uprights on a respective member shiftable relative to said uprights in a direction of the axis of the respective working roll and vertically along the respective upright, the improvement which comprises: a respective cylinder block disposed in each of said windows and vertically guided therein, each of said cylinder blocks being formed with a respective ledge projecting inwardly of the stand and extending parallel to axes of said working rolls;   two pairs of hydraulic bending and balancing cylinders respectively formed in each of said ledges, said pairs of cylinders in each ledge being spaced apart by a distance parallel to said axes greater than the spacing of the cylinders of each pair, said cylinders receiving respective pistons disposed so that a piston of one of the cylinders of each pair acts upon one of said members at the respective upright and the piston of the other cylinder of each pair acts upon the other of said members at the respective upright, and the piston of the cylinders of each ledge alternate therealong in a direction parallel to said axes with respect to the members upon which said pistons act; and   at least one axially effective hydraulic cylinder formed in each of said members and acting upon a journal of the respective working roll to displace said rolls axially.   
     
     
       18. The improvement defined in claim 17 wherein each of said hydraulic bending and balancing cylinders is a double-acting cylinder. 
     
     
       19. The improvement defined in claim 18 wherein said hydraulic bending and balancing cylinders are positioned at the same level in the respective ledge and the axes of said bending and balancing cylinders of each ledge lie in a common substantially vertical plane. 
     
     
       20. The improvement defined in claim 17 wherein said working rolls have their axes offset slightly in a rolling direction from a vertical plane containing the axes of said backing rolls.